Araştırmacılar(10)

• Akalin, Halis
• Akin, Hicran
• Barkay, Orçun
• Binay, Umut Devrim
• Kalkan, Ahmet
• Karakeçili, Faruk
• Kuru, Betül
• Ozdemir, Beyza Ozerten
• Sümer, Betuel
• Sümer, Betül

• ArticleYayıncıda açık erişim2026/r/ebyu/11205
  Diagnosis, management, and prevention of Crimean-Congo haemorrhagic fever: a Delphi-based consensus study in Türkiye

  Ergönül, Önder; Güllü, Deniz; Yigci, Defne; Çelikbaş, Aysel Kocagül; Alay, Handan; Gök, Şebnem Eren; Yapar, Derya; Can, Fatma Kesmez; Kader, Çiğdem; Akdoğan, Özlem

  Background: Crimean-Congo haemorrhagic fever (CCHF) is a widely distributed viral haemorrhagic fever with expanding geographic range. As new regions encounter the disease, clinicians must make high-stakes decisions despite limited standardised management frameworks. Methods: In this multicentre, modified Delphi study, infectious diseases specialists were recruited from 19 centres in Türkiye via an open call through the professional communication channels of the Turkish Society of Clinical Microbiology and Infectious Diseases (known as KLİMİK). Eligibility was determined based on self-reported clinical experience. Eligible participants reported managing more than ten patients with CCHF as primary physicians, with no additional demographic or professional exclusion criteria applied. The Delphi process included three sequential rounds of anonymous online surveys (between Sept 26 2025, and Jan 1, 2026) and an interim structured clarification meeting (Nov 28–29, 2025), to map areas of agreement and heterogeneity across diagnosis, monitoring, therapeutics, and exposure management. Statements were analysed using Likert-scale methodology. Responses were summarised using medians, interquartile ranges, and proportions of agreement. Consensus levels were defined a priori. Findings: Of 45 ID specialists invited to participate in Round 1, 35 completed the questionnaire and were included in the analysis (78% response rate). All 35 eligible participants were invited to Round 2, and 32 (91%) completed the questionnaire. All 32 participants completed Round 3, with no attrition between Rounds 2 and 3. All participants reported experience of managing more than ten patients with CCHF; ∼85% of participants reported managing at least 50 confirmed cases. In total, 146 candidate statements were evaluated, of which 72 achieved early consensus in Round 1. Following iterative refinement, 39 of 56 statements (69.6%) met predefined consensus criteria in the final round, including eight with very high agreement and 22 with high agreement. Strong convergence was observed for early molecular testing and risk-based hospitalisation, ribavirin initiation within 4 days of symptom onset in confirmed cases, risk-adapted transfusion strategies guided by bleeding severity, and post-exposure prophylaxis after high-risk occupational exposure. Persistent heterogeneity remained regarding ribavirin initiation beyond the early symptomatic window, immunomodulatory therapies, and transfusion de-escalation strategies in selected scenarios. Interpretation: These findings should not be interpreted as formal guidelines. By transparently quantifying expert agreement and non-consensus, this study synthesises specialist clinical experience from a high incidence country and delineates areas of convergence and ongoing uncertainty relevant to both endemic and newly affected regions. Prospective studies are needed to validate key therapeutic and management strategies identified in this work. Funding: None. The Authors

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• ArticleYayıncıda açık erişim2026/r/ebyu/10837
  Modified mRNA Encoding the Crimean-Congo Hemorrhagic Fever Virus Nucleocapsid Protein Confers Robust Protection Against Lethal Challenge in Mice

  Keskin, Sercan; Pavel, Shaikh Terkis Islam; Sak, Rabia; Bahadori, Fatemeh; Aslan, Ahmet Furkan; Aktaş, Münir; Karakeçili, Faruk; Kalkan, Ahmet; Özdarendeli, Aykut; Doymaz, Mehmet Ziya

  The Crimean-Congo Hemorrhagic Fever Virus (Orthonairovirus haemorrhagiae) causes a hemorrhagic fever with mortality rates reaching up to 40%. For years, this virus has maintained its position among the top priority pathogens identified by the World Health Organization (WHO). This is due to its endemic presence across a vast region—from Africa and Spain to the Balkans, the Middle East, and throughout Asia—its potential for human-to-human transmission, and the lack of an effective and approved vaccine or treatment. Therefore, the development of an effective vaccine against CCHFV is of critical importance. Building on the success of mRNA-based vaccines during the Coronavirus Disease 2019 (COVID-19) pandemic, this study reports the development of a messenger ribonucleic acid (mRNA) vaccine candidate expressing the nucleocapsid protein (NP) of CCHFV. The CCHFV NP in vitro transcript (IVT) was designed with pseudouridine (Ψ) nucleoside modification. As part of the preclinical characterization of the IVT vaccine candidate, the biochemical and immunological properties of NP were confirmed in Huh-7 cells transfected with IVT NP-ΨmRNA. Afterwards, the efficacy of IVT NP-ΨmRNA immunization was evaluated in immunocompetent BALB/c and transiently immunosuppressed (IS) C57BL/6 mice. In CCHFV challenge studies, IS C57BL/6 mice were used. IS C57BL/6 mice were immunized intramuscularly with 2 doses of IVT NP- ΨmRNA, either naked or encapsulated in Poly(lactic-co-glycolic acid) (PLGA) nanoparticles, administered 14 days apart. High levels of CCHFV NP-specific humoral (IgM and IgG) and cellular (cytokine and lymphoproliferative) responses were demonstrated in BALB/c mice immunized with IVT NP- ΨmRNA. In challenge experiments, 100% survival was observed with both the naked and PLGA-encapsulated IVT NP-ΨmRNA immunizations. These findings demonstrate 100% survival following lethal CCHFV challenge under the experimental conditions tested in this mouse model and support the potential of NP-encoding pseudouridine-modified mRNA vaccines. Additionally, 100% survival was observed in mice immunized with inactivated CCHFV, whereas only 20% survival was detected in the unmodified IVT NP-mRNA vaccinated animals. In the protected mice, viral clearance was observed in the spleen, liver tissues, and blood on day 14 post-challenge. This study demonstrates that NP, the most abundant protein of the virus, is capable of providing significant survival benefits in the tested mouse model. Furthermore, our report represents a significant step in identifying a potential vaccine candidate and provides a solid foundation for further preclinical studies necessary to support future clinical development.

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• ArticleAçık Erişim2026/r/ebyu/10626
  Diagnostic performance of clinical symptom combinations for Crimean-Congo hemorrhagic fever in emergency department patients with reported arthropod bites, stings, or exposure

  Bilgin, Yasin; Sari, Fatih Mehmet; Sakal, Cemalettin; Cimen, Erdem Yakup; Tanrıverdi, Orhan; Yurttutan, Abdullah Emre; Binay, Umut Devrim

  Background: Crimean-Congo hemorrhagic fever (CCHF) is a potentially fatal tick-borne viral disease that remains an important public health problem in endemic regions. Early recognition of CCHF in emergency departments is challenging because initial clinical manifestations are often nonspecific. This study aimed to evaluate the demographic, clinical, and exposure-related characteristics of adult patients presenting to the emergency department after reported or clinically suspected arthropod bites, stings, or contact and to investigate clinical predictors associated with CCHF. Methods: This retrospective single-center study included adult patients presenting to the emergency department after reported or clinically suspected arthropod bites, stings, or contact between October 1, 2023, and October 1, 2024. A total of 526 patients were screened; 24 patients with incomplete data and 2 patients younger than 18 years were excluded. Demographic characteristics, clinical symptoms, and history of tick exposure were recorded. Clinical findings associated with CCHF were analyzed using univariable and multivariable statistical methods. The diagnostic performance of symptom combinations with tick exposure was evaluated using sensitivity, specificity, predictive values, likelihood ratios, odds ratios, and relative risks. Results: A total of 500 adult patients were included, and CCHF was confirmed in 38 patients (7.6%). The mean age was 49.48 ± 15.91 years, and 62.8% of the patients were male. Fever, headache, diffuse body aches, malaise, nausea/vomiting, diarrhea, abdominal pain, rash, ecchymosis, and history of tick exposure were significantly more frequent in CCHF-positive patients (all p < 0.05). CCHF positivity was significantly higher among patients with a history of tick exposure than among those without tick exposure (11.9% vs 3.8%; OR: 3.45, p = 0.001). Among symptom combinations evaluated with tick exposure, diffuse body aches showed the highest specificity (100.0%) and a very high positive likelihood ratio after continuity correction; however, these estimates should be interpreted cautiously because no CCHF-negative patient had this combination. In multivariable logistic regression analysis, malaise (adjusted OR: 117.29, 95% CI: 28.23–487.33, p < 0.001) and fever (adjusted OR: 6.41, 95% CI: 1.87–21.94, p = 0.003) were independently associated with CCHF. Conclusion: Simple clinical findings and symptom combinations may provide valuable early diagnostic clues for CCHF in endemic regions, even before laboratory confirmation. In particular, malaise and diffuse body aches in patients with a history of tick exposure showed high diagnostic performance and may contribute to early recognition and appropriate management of CCHF in emergency department settings.

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• ArticleYayıncıda açık erişim2026/r/ebyu/10410
  Performance of Serum-Based Non-Invasive Fibrosis Scores Compared with Liver Biopsy in Patients with Chronic Hepatitis B

  Binay, Umut Devrim; Karakeçili, Faruk; Barkay, Orçun; Kuru, Betül

  Background and Objectives: Accurate assessment of liver fibrosis is essential for treatment decisions in patients with chronic hepatitis B (CHB). Although liver biopsy is considered the reference standard, its invasive nature limits routine use. Serum-based non-invasive fibrosis scores have been proposed as alternatives; however, their diagnostic performance in CHB remains variable. This study aimed to compare multiple serum-based non-invasive fibrosis scores with liver biopsy findings and to evaluate their association with histological activity. Materials and Methods: This retrospective cross-sectional study included 219 adult patients with CHB who underwent liver biopsy with simultaneous laboratory evaluation. Patients with viral co-infections (HIV, HCV, or HDV), metabolic syndrome, diabetes mellitus, hepatic steatosis, or incomplete data were excluded. Non-invasive fibrosis scores—including APRI, FIB-4, AST/ALT ratio (AAR), age–platelet index (API), GGT-to-platelet ratio (GPR), Lok index, modified Forns index, Albumin–Bilirubin (ALBI) score, and red cell distribution width (RDW)-based indices—were calculated using routine laboratory parameters. Histopathological fibrosis staging served as the reference standard. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis, and areas under the curve (AUC) were compared using the DeLong test. Associations with histological activity index (HAI) were assessed using Spearman correlation. Results: For the prediction of significant fibrosis (≥F2), FIB-4 demonstrated the highest AUC, followed by ALBI and APRI. For advanced fibrosis (≥F3), FIB-4 again showed the highest AUC, followed by APRI and GPR. For significant fibrosis (≥F2), DeLong analysis revealed no statistically significant differences between FIB-4 and the other serum-based scores (p > 0.05). APRI (r = 0.556, p < 0.001) and FIB-4 (r = 0.463, p < 0.001) showed the strongest correlations with HAI. In ROC analysis for moderate-to-severe histological activity (HAI ≥ 4), APRI demonstrated the highest diagnostic accuracy (AUC = 0.677). Conclusions: Serum-based non-invasive fibrosis scores demonstrate comparable but overall modest diagnostic performance for biopsy-confirmed fibrosis in patients with chronic hepatitis B. Indices such as FIB-4 and APRI demonstrated relatively better discrimination and may be considered as screening or rule-out tools in selected clinical contexts. APRI and FIB-4 also show associations with histological activity; however, their clinical application should be interpreted with caution, given their moderate discriminatory capacity.

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• ArticleYayıncıda açık erişim2026/r/ebyu/10335
  Comparison of clinical outcomes associated with RSV and influenza infections in adults: a multicenter study from Türkiye (for AP-TR)

  Akdemir, İrem; Selçuk Özger, Hasan; Hocagil, Tuğba Akkaya; Kayaaslan, Bircan; Alay, Handan; Top, Özge Özgen; Kazak, Esra; Kalın Ünüvar, Gamze; Erbay, Ayşe; Çınar, Güle

  Objectives Respiratory syncytial virus (RSV) is an increasingly recognized cause of serious respiratory illness in adults, yet data from middle-income countries remain scarce. This study aimed to compare clinical outcomes of RSV and influenza virus infections in hospitalized and outpatient adults in Türkiye. Methods This retrospective multicenter study included 3299 adult patients (≥18 years) with polymerase chain reaction-confirmed RSV (n = 628) or influenza (n = 2671) from 21 centers across Türkiye between January 2022 and March 2024. The primary outcome was viral infection–related hospitalization. The secondary composite outcome was intensive care unit (ICU) admission and/or 30-day mortality among hospitalized patients. Propensity score–based overlap weighting was used to adjust for baseline differences including age, risk group, clinical severity, co-infection status, and study center. Results After overlap weighting, RSV infection was not significantly associated with increased hospitalization risk compared to influenza (odds ratio [OR]: 0.96, 95% confidence interval [CI]: 0.77-1.20, P = 0.705). Similarly, no significant difference was observed in the composite outcome of ICU admission or 30-day mortality (OR: 1.40, 95% CI: 0.95-2.05, P = 0.088). Age ≥60 years, high-risk comorbidities, and severe acute respiratory infection presentation were the primary independent predictors of both hospitalization and worse outcomes. Bacterial or fungal co-infections and secondary infections were observed in 12.9% and 7.3% of hospitalized patients, respectively, with no significant difference between RSV and influenza groups. Conclusion After adjustment for baseline characteristics, RSV and influenza were associated with comparable risks of hospitalization and severe clinical outcomes in adults. Host-related factors, particularly older age and underlying comorbidities, were the dominant determinants of adverse outcomes. These findings from a largely unvaccinated, middle-income country cohort highlight the need to expand RSV and influenza vaccination programs targeting high-risk adult populations.

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• ArticleYayıncıda açık erişim2025/r/ebyu/12097
  COVID-19 Incidence and Factors Influencing Infection Risk Among People Living With HIV in Türkiye: Is Current Issue the Vaccine Hesitancy-Opposition?

  Inan, Asuman; Barkay, Orcun; Karapınar, Arda; Yılmaz-Karadag, Fatma; Aktas, Selman; Bolukcu, Sibel

  Introduction: As the Coronavirus Disease-2019 (COVID-19) pandemic intersects with the ongoing Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) crisis, concerns have emerged regarding the susceptibility of people living with HIV/AIDS (PLWH) to severe outcomes from COVID-19. Despite global efforts to understand the interplay between HIV/AIDS and COVID-19, research on this issue remains limited in Türkiye. This study investigates the incidence of COVID-19 among PLWH in Türkiye and factors influencing infection risk. Materials and Methods: An online survey, conducted from April to June 2023, assessed COVID-19 frequency and risk factors among PLWH aged 18 years and older in Türkiye. Demographic data such as age, gender, educational background, underlying health conditions, vaccination status, and COVID-19 infection history were collected from individuals who voluntarily participated. Results: A total of 354 PLWH from 38 cities in Türkiye participated in the study. The median age was 35.8 (range 18–76); 78% were male and 65.5% were university graduates. The rate of experienced COVID-19 among PLWH was 44.6%. Logistic regression analysis revealed that vaccinated individuals had an 84% lower risk of contracting COVID-19 among PLWH. In sum, 80 participants were not vaccinated in this study; of them, 27.5% identified as vaccine opponents and 25% expressed vaccine hesitancy. Discussion: These findings suggest that vaccination status is the key determinant of COVID-19 susceptibility among young and well-educated PLWH in Türkiye. The notable level of vaccine hesitancy and opposition of PLWH highlights the need for public health initiatives aimed at addressing misinformation and enhancing vaccine confidence. Conclusion: This study underscores the urgent need to address vaccine hesitancy and vaccine opposition among educated PLWH in Türkiye. Amid evolving SARS-CoV-2 variants, vaccination remains paramount in mitigating COVID-19 risks among PLWH. Further research should delve deeper into demographic-specific vaccine concerns to optimize public health strategies and meet the unique needs of PLWH communities.

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• ArticleYayıncıda açık erişim2025/r/ebyu/11942
  Intravesical BCG: A Double-Edged Sword? The Untold Story of Infection Risks

  Barkay, Orçun; Keskin, Ercüment

  Background and Objectives: Intravesical Bacillus Calmette-Guérin (BCG) therapy remains a cornerstone in the treatment of non-muscle-invasive bladder carcinoma due to its efficacy in reducing recurrence and progression rates. However, its use is associated with various complications—including urinary tract infections (UTIs)—which necessitates further exploration. This study aims to analyze UTIs occurring during intravesical BCG treatment, emphasizing the microbial spectrum, resistance patterns, and risk factors from an infectious diseases and clinical microbiology perspective. Materials and Methods: A retrospective analysis was conducted on 240 patients diagnosed with non-muscle-invasive bladder carcinoma who received intravesical BCG therapy between 2010 and 2021. Data were collected from hospital records, including demographic characteristics, comorbidities, number of intravesical BCG cycles, and microbiological findings. UTIs were classified based on susceptibility patterns, and statistical analyses were performed to determine associations between clinical variables and UTI risk. Results: UTIs developed in 39.1% (n = 94) of patients, with 25.8% (n = 62) caused by susceptible pathogens and 13.3% (n = 32) by resistant pathogens. The most common causative agent was Escherichia coli (80.7% in susceptible UTIs, 43.8% in resistant UTIs), followed by Pseudomonas aeruginosa and Klebsiella pneumoniae. The presence of diabetes mellitus and chronic kidney disease significantly increased the risk of developing a UTI (p < 0.05). A higher number of intravesical BCG cycles correlated with increased UTI occurrence (p < 0.001). Serum C-reactive protein (CRP) levels were significantly elevated in patients with resistant UTIs, while procalcitonin levels were not a reliable predictor of UTI occurrence. Conclusions: Intravesical BCG therapy is associated with a significant incidence of UTIs, particularly among patients with predisposing comorbidities. The increasing prevalence of antibiotic-resistant infections underscores the need for careful monitoring and targeted antimicrobial stewardship strategies. CRP may serve as a useful adjunctive marker for UTI diagnosis in this setting. Future studies should focus on optimizing infection control measures and refining diagnostic criteria to differentiate between BCG-related inflammation and infectious complications.

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• ArticleAçık Erişim2025/r/ebyu/11866
  Rapid Detection of Pathogens and Resistance Genes Grown in Blood Cultures with Two Multiplex Tandem Real-Time PCR Kits

  Gülhan, Barış; Çıkman, Aytekin; Aydın, Merve; Hasbek, Mürşit; Özekinci, Tuncer; Akyüz, Sümeyye; Karakeçili, Faruk

  Objective: In this study, two multiplex tandem real-time PCR kits were used to rapidly diagnose common Gram-positive cocci and Gram-negative bacilli, detect their commonly seen antibiotic resistance genes, and evaluate the two kits’ performance. Materials and Methods: Gram-positive 12 (GP-12) kit (AusDiagnostics, Australia) and Gram-negative 12 (GN-12) kit (AusDiagnostics, Australia) were used in the study. Seventy-eight Gram-negative bacilli and 54 Gram-positive cocci grown in blood culture vials were applied to GN-12 and GP-12 panels. At the same time, the passages of the samples were made and incubated. After that, identification and antibiograms were made in the Phoenix™ automated system (Becton, Dickinson and Company, USA) and VITEK 2 Compact automated system (bioMérieux, France). Results: Twenty-one Staphylococcus aureus, twelve coagulase-negative staphylococci (CoNS), two Streptococcus pneumoniae, two Enterococcus faecium, and three Enterococcus faecalis were found to match the results from the automated GP-12 Kit. Pathogens present in the panel were successfully identified using the GN-12 kit. Both panels were found to be more effective in diagnosing polymicrobial infections. Conclusion: These evaluated kits were rapid (approximately three hours) and valuable in identifying common sepsis pathogens and resistance genes. Thus, these tests can easily be used in the diagnosis of sepsis.

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• ArticleYayıncıda açık erişim2025/r/ebyu/11558
  Key predictors of mortality in Crimean-Congo haemorrhagic fever: a retrospective multicentre cohort study

  Güllü, Deniz; Yigci, Defne; Baykam, Nurcan; Çelikbaş, Aysel Kocagül; Yapar, Derya; Akdoğan, Özlem; Özden, Kemalettin; Sarıkaya, Rukiye İnan; Hasanoğlu, İmran; Güner, Rahmet

  Objective This study aimed to identify key predictors of mortality in patients with Crimean-Congo haemorrhagic fever (CCHF). Our specific goals included characterizing the demographic and clinical features of hospitalized CCHF patients in Türkiye, determining the factors associated with mortality among these patients, and evaluating the impact of early ribavirin administration. Methods A retrospective study was conducted on 1103 CCHF patients across 18 hospitals in Türkiye from 1 January 2019 to 20 November 2024. All data were obtained via an online data collection system by the designated physician at each centre. Patients with laboratory-confirmed CCHF infection who were hospitalized were included in the study. Univariate analyses and time-dependent Cox regression were conducted. Results Of the 1103 patients, 65.7% (725/1102) were men; 87.2% (962/1103) resided in rural areas; and the mean age was 53 years. Ticks were identified as the transmission route in 68.4% (755/1103) of the cases. Comorbidities included diabetes mellitus, chronic heart disease, and hypertension; 4.6% (51/1103) of the patients developed healthcare-related infections. Intensive care unit admission was required in 8.0% (88/1103) of the patients, and the overall mortality rate was 5.1% (56/1103). In univariate analyses, age ≥50 years (odds ratio [OR], 3.1; 95% CI, 1.58–6.08; p < 0.001) and diabetes mellitus (OR, 4.49; 95% CI, 2.20–9.18; p < 0.001) were associated with increased mortality. Both variables remained statistically significant predictors in the multivariate analysis. Although early ribavirin administration, ≤96 hours from symptom onset, did not reach statistical significance in univariate analysis (OR, 0.52; 95% CI, 0.26–1.05; p = 0.065), it was significantly associated with reduced mortality in time-dependent Cox regression (adjusted hazard ratios, 0.21; 95% CI, 0.07–0.69; p = 0.010). Discussion Key factors such as age and comorbidities can predict mortality in CCHF patients. Timely identification of these predictors, along with early administration of ribavirin, may contribute to improved survival and better clinical outcomes.

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• ArticleAçık Erişim2025/r/ebyu/11429
  Effect of serum magnesium level on carotid intima media thickness in hemodialysis patients

  Kara, Ali Veysel; Ozdemir, Ridvan; Inan, Hamza; Ozdemir, Beyza Ozerten; Hayme, Serhat; Cosgun, Muharrem Said

  Background: We aimed to examine whether serum magnesium level is related to cardiovascular events in hemodialysis patients by investigating the relationship between serum magnesium (Mg) level and carotid intima media thickness (CIMT). Methods: In this cross-sectional study, we evaluated 88 hemodialysis patients. The mean CIMT of these patients was measured and recorded by doppler ultrasonography. Patients were divided into two groups according to their serum magnesium level. Correlation analysis and linear regression analysis were used to define the relationship between study parameters. We divided our patients into 2 groups according to Mg value as group 1 (Mg ≥ 2.3 mg/dl) and group 2 (Mg < 2.3 mg/dl). Results: The mean CIMT of patients with group 1 and group 2 were respectively 0.93 ± 0.22 mm and 1.03 ± 0.22 mm. There was statistically significant difference between two groups in terms of the mean CIMT value (p = 0.045). We found negative, low-level, statistically significant correlations between Mg and mean CIMT ​​(r=-0.272; p = 0.010), calcium and mean CIMT (r: -0.221, p: 0.039) and hemoglobin and mean CIMT (r: -0.215, p: 0.044). According to regression analysis, serum magnesium level and age were found independent risk factors for mean CIMT value (p: 0.004 and p: 0.045). Conclusions: We found a significant relationship between serum Mg level and CIMT, which indicates carotid atherosclerosis.

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